科学揭秘：罗马帝国灭亡的真正原因

　　Oak rings are sensitive to changes in precipitation, and can show changes according to what was happening in the environment。

　　树木的年轮对于降水量的变化十分的敏感，它记录了不同时期的环境状况以及变化。

　　The research could also glean signs about what was happening from changes in how many trees were being cut。

　　这项研究还收集了有关于树木减少所导致的环境改变之间的联系。

　　The study said: 'Reduced tree harvesting around AD 250 to 400 coincides with the biggest central Europe historical crisis, the Migration Period, a time marked by lasting political turmoil, cultural change and socio-economic instability。

　　研究称，公元250年到400年间，树木被大量的砍伐，与此同时恰逢欧洲大陆正遭受着有史以来最大的危机，大迁移，此时标志性的社会现象包括了政治更迭、文化变迁以及经历衰退。

　　'Increasing timber harvest for construction is represented by abundant felling parallel to socio-economic consolidation from the sixth to the ninth centuries.'

　　因建筑需求所而引发的大规模的伐木行为，正好出现在了社会经济趋于平稳的六世纪到九世纪之间。

　　The scientists said 'unfavourable climate may have contributed to the spread of the second plague pandemic, the Black Death, which reduced central Europe's population after AD 1347 by 40 to 60 percent.'

　　科学家们还表示，不利的天气条件也助涨了第二次的鼠疫大爆发，黑死病，这些流行病的传染导致了1347之后欧洲人口骤减四到六成。

　　Researchers also noted that a sharp decline in North American temperatures around the same time saw an 'abrupt desertion of former Greenland settlements'。

　　研究人员还指出，北美地区在同时期出现了气温剧烈下降的情况，从而迫使了大批人口从格林兰岛迁出。

　　Technological advances have made the modern human population less vulnerable to environmental changes to a certain extent, the study said。

　　随着科学技术的进步，人类受到气候环境变化的影响也越来越小。

　　However we are 'certainly not immune to the predicted temperature and precipitation changes, especially considering that migration to more favourable habitats as an adaptive response will not be an option in an increasingly crowded world.'

　　尽管如此，我们并不能幸免于可预知的气温及降水变化，而在这个日益拥挤的世界里，迁移已经不再是一个选择和适应环境的办法了。